Rock gnomes are a common type of gnomes, and are usually the only sort that surface dwellers ever see. Rock gnomes are inquisitive, irrepressive, and at times insincere. Equipped by nature with keen curiosity and a knack for mechanical workings, gnomes excel at intricate crafts such as gemcutting, toymaking, and clockwork engineering. They happen to be fine gunsmiths and they are the most likely of any race to arm themselves with smokepower firearms.

[Source: Forgotten Realms Campaign Setting by Greenwood, Reynolds, Williams, and Heinsoo, published by Wizards of the Coast, page 16.]